Canadian device allows deaf to 'hear' music through skin

A chair that allows the hearing-impaired to experience music in a new way will be featured at a concert in Toronto designed for deaf people.

The Emoti-Chair is a three-year venture developed at Ryerson University's centre for learning technologies in conjunction with the science of music, auditory research and technology (SMART) lab.

The idea is to treat the skin as a hearing membrane, said Carmen Branje, one of the Ryerson researchers.

Branje, 26, who has a bachelor's degree in computing science and a master's in management science, also plays drums in the Toronto punk rock band Hollywood Swank, one of the groups that will be performing at the concert on Thursday.

David Fourney, a PhD candidate with Ryerson's mechanical engineering program, had the chance to use the Emoti-Chair.

CBC News : I'm fascinated with the idea that the skin can be used to detect sound.

Fourney : "The skin is the body's largest organ. One of its main properties is that is designed for touch. As a hard-of-hearing person, I can tell you that for me, hearing sound is like another form of touch.

"Have you ever felt a sound that literally tickled your ear? Did you know that sound can actually move the hairs in your ear canal? I know, because I have experienced it. I have actually felt it. Sound can actually be ticklish.

"I am profoundly deaf in one ear and moderately hard of hearing in the other. The ear that hears seems to ignore everything else except the actual sensation of hearing the sound. The ear that does not hear ignores the entire sensation of hearing the sound, but can sense the presence of sound through the feeling it will create as it moves the hairs in my ear.

"If you do not wear shoes while listening to a stereo, you can feel the sound through your feet. With years of experience, you can train your body to know what it is you are "hearing" — high tones, low tones, something in the middle, etc."

CBC News : "Do different sound frequencies detected through the skin evoke a different feeling —emotion?"

Fourney:"Absolutely. Feelings, emotions, flashbacks. The experience is very much the same. The means of enjoying the experience is different.

CBC News : "Music can carry away a listener. Can sound vibrations have the same effect for a person who's deaf?"

Fourney : "Yes they can. In the Emoti-Chair, you can feel a wave of tactile feeling just wash over you. It can be a real rush of emotion. When you tune out everything else — just close your eyes and focus on the sensation — you can be carried away in the same sense.

"One of the custom designed tracks — we call them 'vibe-tracks' — that have been developed for the Emoti-Chair has a trilling sound that feels like someone's fingers are dancing on your back. Its really cool."

Prototypes of the Emoti-Chair will be on display at the event, which will be held at Clinton's Tavern in downtown Toronto.

One chair features 16 speakers embedded along the back and arms to stimulate the user’s tactile senses. Another prototype features 14 speakers but also includes rocking motions that are activated when a certain drum is struck.

In the past, the only ways deaf people could experience music was to feel sound waves passing through them, or to physically press their hands or face to the speaker.

The Emoti-Chair does two things: It breaks the sound frequencies up so that the user feels the piano through one speaker, the guitar through another and so on. It also changes high-frequency sounds into something that is detectable to a deaf person.

Most people are familiar with the pounding sensation that occurs when the bass is turned way up on a speaker. Skin can distinguish between low-level sound frequencies up to about 1,000 Hz, and it can detect frequencies up to 2,000 Hz. However, it's debatable whether a person could distinguish between, say, 1,500 and 2,000 Hz, Branje said.

The human ear can detect between 20 and 20,000 Hz. Anything above that is dog-whistle territory, Branje said.

Luckily, many instruments produce music that falls within the skin-detection range. For instance, the skin can detect three quarters of the sounds produced by a piano. So Branje's team worked with that.

They determined they could compress the frequencies of higher sounds and boost the lower frequencies to allow deaf people to feel sound levels that that might have been aural gaps in the past.

Senior citizens 'hear' classical music

They knew they were on to something when they had senior citizens who were born deaf sit in the chairs and listen to classical music.

"Their first reaction was to conduct, because they knew it was classical music," Branje told CBC News.

Branje sees other applications for the Emoti-Chair, including using it as a teaching tool for deaf children. Kids who have cochlear implants could also sit in the chair and get that much more information.

In addition to the Emoti-Chair, the concert will also feature MusicViz, which was developed by David Fourney, a hearing-impaired PhD candidate in Ryerson's mechanical engineering program.

MusicViz is designed to further enhance the Emoti-Chair by visualizing music though animation and graphics. Colours generated by a software program are synced with individual notes and sounds, then projected on to a screen in a fan-shaped pattern with different hues.

That makes the music experience not just a tactile music experience, but also a visual one.